Clinical Performance of Self-Collected Nasal Swabs and Antigen Rapid Tests for SARS-CoV-2 Detection in Resource-Poor Settings

Sitoe, Nádia; Sambo, Júlia; Mabunda, Nédio; Nguenha, Neuza; Chilaúle, Jorfélia; Rafael, Júlio; Macicame, Anésio; Chelene, Imelda; Mudenyanga, Chishamiso; Sacks, Jillian; Viegas, Sofía; Loquiha, Osvaldo; Jani, Ilesh

doi:10.3390/biomedicines10092327

Cited by 6 publications

(2 citation statements)

References 29 publications

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“…Most of the research on self-testing actually assessed self-sampling and not the complete self-testing process. Such studies indicated that high quality samples can be taken by users, with self-taken samples tested against PCR yielding sensitivities and specificities close to, or above the WHO's target product profile recommended sensitivity and specificity thresholds of 80% and 97% [22][23][24][25][26][27][29][30][31]. Regarding the complete self-testing process (i.e.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of COVID-19 antigen rapid diagnostic tests for self-testing in Lesotho and Zambia

Bresser,

Erhardt,

Shanaube

et al. 2024

PLoS ONE

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Introduction The use of antigen rapid tests (Ag-RDTs) for self-testing is an important element of the COVID-19 control strategy and has been widely supported. However, scale-up of self-testing for COVID-19 in sub-Saharan Africa is still insufficient and there is limited evidence on the acceptability of self-testing and agreement between Ag-RDT self-testing and Ag-RDT testing by professional users. A joint collaboration (Botnar Research Centre for Child Health-European & Developing countries Clinical Trials Partnership)was established between Lesotho and Zambia to address these gaps in relation to Ag-RDT self-testing and contribute to increasing its use in the region. Methods A cross-sectional study was conducted with qualitative and quantitative data analysis. Firstly, 14 in-depth cognitive interviews (5 in Zambia and 9 in Lesotho) were performed to assess the participants’ understanding of the instructions for use (IFU) for self-testing. In a second step, evaluation of test agreement between Ag-RDT self-testing and Ag-RDT testing by professional user using SD Biosensor STANDARD Q COVID-19 Ag-RDT was performed. In Zambia, usability and acceptability of self-testing were also assessed. Results Cognitive interviews in Lesotho and Zambia showed overall good understanding of IFU. In Zambia, acceptability of self-testing was high, though some participants had difficulties in conducting certain steps in the IFU correctly. Agreement between Ag-RDT self-test and Ag-RDT by professional users in Lesotho (428 participants) and Zambia (1136 participants) was high, 97.3% (403/414, 95% CI: 95.3–98.7) and 99.8% (1116/1118, 95% CI: 99.4–100) respectively. Conclusion Findings from this study support the use of Ag-RDT self-testing within COVID-19 control strategies in sub-Saharan Africa, contributing to increase the testing capacity and access in hard-to reach settings.

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Section: Discussionmentioning

confidence: 99%

Evaluation of COVID-19 antigen rapid diagnostic tests for self-testing in Lesotho and Zambia

Bresser,

Erhardt,

Shanaube

et al. 2024

PLoS ONE

View full text Add to dashboard Cite

show abstract

“…Most of the research on self-testing actually assessed self-sampling and not the complete self-testing process. Such studies indicated that high quality samples can be taken by users, with self-taken samples tested against PCR yielding sensitivities and specificities close to, or above the WHO's target product profile recommended sensitivity and specificity thresholds of 80% and 97% (19)(20)(21)(22)(23)(24)(26)(27)(28). Regarding the complete self-testing process (i.e.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of Covid-19 Ag-RDTs self-testing in Lesotho and Zambia

Bresser

Erhardt

Shanaube

et al. 2022

Preprint

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Background The use of antigen rapid tests (Ag-RDTs) for self-testing is an important element of the COVID-19 control strategy and has been widely supported. However, scale-up of self-testing for COVID-19 in sub-Saharan Africa is still insufficient and there is limited evidence on the acceptability of self-testing and agreement between Ag-RDT self-testing and Ag-RDT testing by professional users. A joint collaboration (BRCCH-EDCTP COVID-19 Initiative) was established between Lesotho and Zambia to address these gaps in relation to Ag-RDT self-testing and contribute to increasing its use in the region. Methods A cross-sectional study was conducted with qualitative and quantitative data analysis. Firstly, 11 in-depth cognitive interviews (5 in Zambia and 9 in Lesotho) were performed to assess the participants’ understanding of the instructions for use (IFU) for self-testing. In a second step, evaluation of test agreement between Ag-RDT self-testing and Ag-RDT testing by professional user using SD Biosensor STANDARD Q COVID-19 Ag-RDT was performed. In Zambia, usability and acceptability of self-testing were also assessed. Results Cognitive interviews in Lesotho and Zambia showed overall good understanding of IFU. In Zambia, acceptability of self-testing was high, though some participants had difficulties in conducting certain steps in the IFU correctly. Agreement between Ag-RDT self-test and Ag-RDT by professional users in Lesotho (428 participants) and Zambia (1136 participants) was high, 97.6% (404/414, 95% CI: 95.6-99.8) and 99.8% (1116/1118, 95% CI: 99.4-100) respectively. Conclusion Findings from this study support the use of Ag-RDT self-testing within COVID-19 control strategies in sub-Saharan Africa, contributing to increase the testing capacity and access in hard-to reach settings.

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Diagnostic performance of LumiraDx SARS-CoV-2 rapid antigen test compared to PCR for diagnosis of COVID-19 in Liberia

Badio,

Lindan,

Johnson

et al. 2023

Preprint

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BackgroundDiagnosis of SARS-CoV-2 infection in Liberia has primarily relied on polymerase chain reaction (PCR)-based testing at the country’s National Reference Laboratory. This centralized approach caused reporting delays, prompting evaluation of point-of-care antigen-based tests. We assessed the test performance of the LumiraDx™ SARS-CoV-2 Ag test (LumiraDx™, London, UK) in this setting.MethodsWe tested ambulatory individuals screened for enrollment into an observational cohort study of COVID-19 sequelae in Monrovia in 2021. We compared the results of LumiraDx testing of anterior nasal swab specimens to the results of PCR BioFire® R2.1P (bioMérieux, Salt Lake City, Utah) on eluent from nasopharyngeal swabs.ResultsWe evaluated 348 individuals. Among the 274 persons with symptoms, 49.3% were PCR-positive and 36.5% were antigen-positive. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of LumiraDx in this group were 72.6% (95% CI: 64.3%-79.9%), 98.6% (95% CI: 94.9%-99.8%), 78.7% (CI: 71.9%-84.6%), and 98.0% (CI: 93.0%-99.8%), respectively. Among the 74 asymptomatic individuals, 12.2% were positive by PCR, and 5.5% by antigen testing, resulting in a sensitivity, specificity, NPV, and PPV of LumiraDx of 44.4% (95% CI: 13.7%-78.8%), 100% (95% CI: 94.5%-100%), 92.9% (CI: 84.1%-97.6%), and 100% (CI: 39.8%-100%), respectively.ConclusionAlthough the specificity and PPV of LumiraDx for diagnosing SARS-CoV-2 were high among persons with and without symptoms, the sensitivity was unacceptably low in both groups, and much less than that reported by the manufacturer. Before new point-of-care diagnostics are adopted, test performance needs to be assessed in the local setting.

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Clinical Performance of Self-Collected Nasal Swabs and Antigen Rapid Tests for SARS-CoV-2 Detection in Resource-Poor Settings

Cited by 6 publications

References 29 publications

Evaluation of COVID-19 antigen rapid diagnostic tests for self-testing in Lesotho and Zambia

Evaluation of COVID-19 antigen rapid diagnostic tests for self-testing in Lesotho and Zambia

Evaluation of Covid-19 Ag-RDTs self-testing in Lesotho and Zambia

Diagnostic performance of LumiraDx SARS-CoV-2 rapid antigen test compared to PCR for diagnosis of COVID-19 in Liberia

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